sciencehabit writes: All you graying, half-deaf Def Leppard fans, listen up. A drug applied to the ears of mice deafened by noise can restore some hearing in the animals. By blocking a key protein, the drug allows sound-sensing cells that are damaged by noise to regrow. The treatment isn't anywhere near ready for use in humans, but the advance at least raises the prospect of restoring hearing to some deafened people.